On Mon, 13 Oct 2008 11:11:49 +0100, Ian & Hilda Dedic wrote:

I rang our usual plumber chap who said "your heat exchangers cracked---
you need a new boiler!"

The good news is that the heat exchanger is probably not cracked: there
are 'O'-rings that seal the ends to the unions with the pipework at the
left side, and to blanking plates at the right side, and it's probably just
these that are knackered.

The bad news is that it still requires a major dismantling of the boiler
to get at them and I suspect it's a persistent problem with the material
of the rings not being up to the job. Last time I had to do this job W-B
spun me a line about how the system couldn't have been properly flushed
out (which it had no specific warning about anyway) and that it was
un-flushed-out crud accumulating in the heat exchanger causing hot spots
which in turn were causing damage to the O-rings. However I didn't find
any noticeable amount of crud deposited in the h-x and I did notice that
the colour of the rings was differnt to the last set (grey rather than
black IIRC) suggesting they'd changed the formulation.

Whether you choose to bite the bullet and go for a new boiler rather than
throw good money into what is probably not Worcester's most reliable
example of conventional-tech boiler (the only one in the range with a
cast-iron heat exchanger AFAIK) is up to you.

--
YAPH http://yaph.co.uk

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